First-principles study of the SiNx/TiN(001) interface
2012 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 85, no 10, 104106- p.Article in journal (Refereed) Published
The structure of the SiNx tissue phase in superhard TiN/SiNx nanocomposites has been debated in the literature. We present a theoretical investigation of the possibility of crystalline and coherent ( 001) interfaces that satisfies the two necessary criteria, stability with respect to lattice vibrations as well as to variations in stoichiometry. It is found that one monolayer of Si tetrahedrally coordinated by N in a B3-like geometry embedded between B1-TiN( 001) surfaces is both dynamically stable and thermodynamically stable with respect to vacancy formation. However, with increasing layer thickness the B3-type structure becomes unstable with respect to Si vacancy formation. Instead we suggest that a tetragonal D0(22)-like order of Si vacancies can stabilize the interface. These structures are in line with the experimental findings of the crystalline tissue phase which has coherent interfaces with TiN.
Place, publisher, year, edition, pages
American Physical Society , 2012. Vol. 85, no 10, 104106- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-76187DOI: 10.1103/PhysRevB.85.104106ISI: 000301334700002OAI: oai:DiVA.org:liu-76187DiVA: diva2:513212